A Distributed Conductance Cross-Correlation Method for Measuring Low-Velocity and High Water-Cut Oil-Water Flows

Abstract Single-layer water cut measurement is of great significance for identifying and shutting off the unwanted water, analyzing oil remained and optimizing production. Currently, however, only the water cut of multilayer mixture can be measured by testing samples taken from wellhead, a way which is widely used in oilfields. That of single-layer fluid cannot be determined yet To address the problem, this paper puts forward a new impedance sensor that offers long-term online monitoring of single-layer water cut. This sensor is based on the different electrical conductivity of oil and water. It has two layers. The inner one contains three electrodes - two at both sides sending sinusoidal excitation signals and one at the middle receiving signals that have been attenuated by the water-oil medium. With the Maxwell's model of oil-water mixed fluid, the receiver then can measure the water cut online. The outer layer of the sensor is made of PEEK, an insulative protection. In front of the electrodes lies a static mixer which makes the measurement more accurate by fully blending the two media when they flow through the electrodes. Laboratory tests are carried out with the prototype of the sensor at various oil-water mixing ratios, fluid flow rates, and temperatures. Results show that the average margin of error is within ± 3%. Higher accuracy is seen when high water cut and flow rate enable oil globules to disperse more evenly and the space in between to get wider and the RMS error is less than 2%. If the water cut drops below 80%, the aggregation of the droplets will cause wild fluctuation and more errors in the measurement. In addition, the mineralization of the mixture directly changes its conductivity, which largely impacts the result. Meanwhile, temperature can influence the ionic movement intensity and then alter the conductivity of the medium. Therefore, in practice, the sensor calibration needs to be performed according to the range of medium salinity, and the temperature of the medium is collected in real time for temperature compensation. It is shown that after the adjustment, the water cut measurement results have higher accuracy and consistency. The impedance sensor can realize online water cut monitoring for a single-layer, indicated by tests. It is more suitable for the increasing high water cut oilfields in that it is more accurate as the water cut grows.

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Real-Time EM Look-Ahead Resistivity for Mapping of Oil/Water Contact While Drilling at Low Deviated Well, New Perspective for Mature Oil Fields Development: A Case Study Of Umm Gudair Field, Kuwait

10.2118/205218-ms ◽

2021 ◽

Author(s):

Nasser Faisal Al-Khalifa ◽

Mohammed Farouk Hassan ◽

Deepak Joshi ◽

Asheshwar Tiwary ◽

Ihsan Taufik Pasaribu ◽

...

Keyword(s):

Water Saturation ◽

High Water ◽

Carbonate Reservoir ◽

Water Contact ◽

Saturation Zone ◽

Look Ahead ◽

Production History ◽

Oil Water ◽

High Water Cut ◽

Water Cut

Abstract The Umm Gudair (UG) Field is a carbonate reservoir of West Kuwait with more than 57 years of production history. The average water cut of the field reached closed to 60 percent due to a long history of production and regulating drawdown in a different part of the field, consequentially undulating the current oil/water contact (COWC). As a result, there is high uncertainty of the current oil/water contact (COWC) that impacts the drilling strategy in the field. The typical approach used to develop the field in the lower part of carbonate is to drill deviated wells to original oil/water contact (OOWC) to know the saturation profile and later cement back up to above the high-water saturation zone and then perforate with standoff. This method has not shown encouraging results, and a high water cut presence remains. An innovative solution is required with a technology that can give a proactive approach while drilling to indicate approaching current oil/water contact and geo-stop drilling to give optimal standoff between the bit and the detected water contact (COWC). Recent development of electromagnetic (EM) look-ahead resistivity technology was considered and first implemented in the Umm Gudair (UG) Field. It is an electromagnetic-based signal that can detect the resistivity features ahead of the bit while drilling and enables proactive decisions to reduce drilling and geological or reservoir risks related to the well placement challenges.

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Prediction of oil-water relative permeability with a fractal method in ultra-high water cut stage

International Journal of Heat and Mass Transfer ◽

10.1016/j.ijheatmasstransfer.2018.11.011 ◽

2019 ◽

Vol 130 ◽

pp. 1045-1052 ◽

Cited By ~ 3

Author(s):

Cuo Guan ◽

Wenrui Hu ◽

Yiqiang Li ◽

Ruicheng Ma ◽

Zilin Ma

Keyword(s):

Relative Permeability ◽

High Water ◽

Fractal Method ◽

Oil Water ◽

High Water Cut Stage ◽

High Water Cut ◽

Water Cut

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Optimization Design for Oil-Water Separator of Injection-Production Technology in the same Well

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.803.383 ◽

2013 ◽

Vol 803 ◽

pp. 383-386

Author(s):

Shu Ren Yang ◽

Di Xu ◽

Chao Yu ◽

Jia Wei Fan ◽

Cheng Chu Yue Fu

Keyword(s):

Production Technology ◽

Optimization Design ◽

Large Scale ◽

High Water ◽

Oil Field ◽

Production Costs ◽

Water Separator ◽

Oil Water ◽

High Water Cut ◽

Water Cut

In order to solve the problem of high water cut wells in some oil field in Daqing that it could not get the large-scale application because of the bad separating effect of down hole centrifugal oil-water separator, we optimize the design of multi-cup uniform flux oil-water separator according to the similar separation principle of multi-cup uniform flux gas anchor, and it is obtained to achieve of injection-production technology in the same well which is of high water cut. The design concept of the separator is increasing the number of opening every layer and aperture gradually in subsection from up to down in the design process. The purpose is to get the close intake quantity of every orifice and guarantee the residence time is long enough in the separator, effectively shorten the length of down hole oil-water separator and reduce the production costs and operating costs.

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Flow measurement of oil-in-water flows in vertical low flow rate and high water-cut flow conditions

Journal of Physics Conference Series ◽

10.1088/1742-6596/1065/9/092010 ◽

2018 ◽

Vol 1065 ◽

pp. 092010

Author(s):

D Y Wang ◽

N D Jin ◽

Y S He ◽

L S Zhai ◽

Y Y Ren

Keyword(s):

Flow Rate ◽

Flow Measurement ◽

High Water ◽

Low Flow ◽

Flow Conditions ◽

Water Flows ◽

Oil In Water ◽

High Water Cut ◽

Water Cut ◽

Low Flow Rate

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Effects of oil viscosity on waterflooding: A case study of high water-cut sandstone oilfield in Kazakhstan

Open Geosciences ◽

10.1515/geo-2020-0218 ◽

2020 ◽

Vol 12 (1) ◽

pp. 1736-1749

Author(s):

Jincai Wang ◽

Zifei Fan ◽

Lun Zhao ◽

Li Chen ◽

Jun Ni ◽

...

Keyword(s):

High Water ◽

High Viscosity ◽

Oil Wells ◽

Oil Reservoirs ◽

Low Viscosity ◽

Well Pattern ◽

Remaining Oil ◽

Oil Water ◽

High Water Cut ◽

Water Cut

Abstract After a sandstone oilfield enters the high water-cut period, the viscosity of crude oil has an important influence on remaining oil distribution and waterflooding characteristics under the same factors of, e.g., reservoir quality and development methods. Based on a comprehensive interpretation of the waterflooded layers in new oil wells, physical simulation experiments, and reservoir numerical simulations, we analyzed the waterflooding laws of a high water-cut sandstone reservoir with different oil viscosities in Kazakhstan under the same oil production speed, and we clarified the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The results show that low-viscosity oil reservoirs (1 mPa s) have uniform waterflooding, thick streamlines, small waterflooding areas, and low overall waterflooding degrees because of their homogeneous oil–water viscosities. However, within waterflooded areas, the reservoirs have high oil displacement efficiencies and high waterflooding degrees, and the remaining oil is mainly concentrated in the unwaterflooded areas; therefore, the initial production and water cut in new oil wells vary significantly. High-viscosity oil reservoirs (200 mPa s) have severe waterflooding fingering, large waterflooding areas, and high overall waterflooded degrees because of their high oil–water mobility ratios. However, within waterflooded areas, the reservoirs have low oil displacement efficiencies and low waterflooding degrees, and the remaining oil is mainly concentrated in both the waterflooded areas and the unwaterflooded areas; therefore, the differences in the initial production and water cut of new oil wells are small. Moderate-viscosity oil reservoirs (20 mPa s) are characterized by remaining oil distributions that are somewhere in between those of the former two reservoirs. Therefore, in the high water-cut period, as the viscosity of crude oil increases, the efficiency of waterflooding gradually deteriorates and the remaining oil potential increases. In the later development, it is suggested to implement the local well pattern thickening in the remaining oil enrichment area for reservoirs with low viscosity, whereas a gradual overall well pattern thickening strategy is recommended for whole reservoirs with moderate and high viscosity. The findings of this study can aid better understanding of waterflooding law and the remaining oil potential of reservoirs with different viscosities and proposed corresponding development measures. The research results have important guidance and reference significance for the secondary development of high water-cut sandstone oilfields.

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